Branched-chain polyesters have a wide variety of applications. Their high molecular weight and low crystallinity makes them attractive for use in adhesive compositions, personal and consumer care compositions, as plasticizers and rheology modifiers, and the like. Such compounds are typically derived from certain short-chain dicarboxylic acids, such as adipic acid. Thus, such compounds may be unsuitable for certain applications, especially where it may be desirable that the polyester contain longer-chain hydrophobic portions.
The self-metathesis of natural oils, such as soybean oil, provides one means of making branched-chain polyesters having longer-chain hydrophobic portions. Certain such methods are disclosed in U.S. Patent Application Publication No. 2013/0344012. But, using such methods, it is still difficult to obtain branched-chain polyester compositions having a higher molecular weight, such as molecular weights corresponding to oligomers containing, on average, about 5-6 triglycerides or more. Obtaining higher molecular-weight oligomers using such methods presents a number of difficulties, including practical limits on the time and the quality of the vacuum needed to remove the product olefins to drive the reaction toward making higher-molecular-weight oligomers.
Thus, while using self-metathesis of natural oils provides a useful means of obtaining branched-chain polyesters, there remains a continuing need to develop processes that would allow for the practical synthesis of higher-weight glyceride oligomers.